image: This is a day gecko Phelsuma ornata with a blossom Gastonia mauritiana on the island of Mauritius. view more
Credit: Christopher Kaiser-Bunbury
In a human-dominated world that contains only little "historical" nature, the term ecosystem can no longer be a synonym for unspoilt nature. The term "novel ecosystems" was coined a few years ago to describe disturbed ecosystems, in which biodiversity has been significantly altered as the result of human intervention. "In our new conservation framework we argue that this strict distinction between historic and novel ecosystems should be reconsidered to aid conservation", pollination biologist Dr. Christopher Kaiser-Bunbury describes the approach, which is not without controversy.
On continents with vast natural parks, such as the USA and Africa, critics fear that the new concept could weaken the protection of historic nature by, for instance, redirecting financial resources towards more active intervention and design of ecosystems. The team of Darmstadt and Zurich biologists, however, propagates a reconciling approach. "Our framework combines strategies that were, until now, considered incompatible. Not only historic wildlands are worth protecting, but also designed cultural landscapes. Given the increased anthropogenic pressure on nature, we propose a multi-facetted approach to preserve biodiversity: to protect historic nature where ecologically viable; to actively create new, intensively managed ecosystems; to accept novel ecosystems as natural, wild landscapes; and to convert agricultural and other cultivated landscapes while generally maintaining land-use priorities."
Agricultural landscapes "of little value" belong on the agenda
New ecosystems may also include maize fields and banana plantations, as agricultural land can be used to preserve biodiversity. In fact, necessary measures are relatively easy to implement and comparatively inexpensive. In India, for example, native trees are planted in and adjacent to coffee plantations to attract native pollinator species, which increase the yield and quality of the coffee. In the USA similar strategies are applied to secure pollination services of almond and melon plantations and provide habitat for native biodiversity at the same time. Trials in Europe involving hedges and meadow strips along fields have shown that many animal species use these areas for feeding and nesting. Such modifications also create corridors between habitats that are traditionally worth protecting. "The individual measures proposed here are not novel but what is needed is an overall concept that combines these measures on a landscape level. And this is something that has been tested on many oceanic islands – with considerable success."
Lessons from islands
The studies by the Darmstadt and Swiss biologists have shown that biodiversity conservation on regionally heterogeneous islands, such as Galapagos, Hawaii, Fiji or Seychelles, illustrates the successful implementation of such an integrated concept. On the Seychelles, for instance, the combined conservation measures include the strict protection of natural cloud forest on a few mountain tops, the management of abandoned cinnamon plantations, and green urban areas such as gardens. The recovery of threatened species and a halt to the decline of native biodiversity are indicators of the success of these conservation strategies. "The examples from Seychelles mirror similar conservation efforts on many islands independent of their specific ecological problems. The lessons show that a mix of conservation strategies should thus be upscaled to the landscape level elsewhere to tackle biodiversity loss."
"Some species cannot be saved"
An important rationale of the proposed conservation framework is to maximise the effective use of financial and natural resources. "We must prioritise species and habitats for active management. There are numerous threatened species which cannot be saved from extinction. Instead we should focus our efforts on species that are important for the functioning of an ecosystem or evolutionary distinct. Those species of historic nature should be preserved with the most elaborate and costly management interventions to sustain viable populations – including ex situ management techniques in zoos or botanical gardens. "We have to make use of what is left in nature, at the same time we need target our efforts."
In another study the ecologists aim to investigate how the concept developed on islands can bet intensively tested in different landscape settings, including on a larger scale on continents.
Full reference:
Kueffer, C. and C. N. Kaiser-Bunbury. Reconciling conflicting perspectives for biodiversity conservation in the Anthropocene. Frontiers in Ecology and the Environment. In press. doi:10.1890/120201
Contacts:
Dr. Christoper Kaiser-Bunbury, tel. +49 (0) 6151 167 5413,
ckaiser-bunbury@bio.tu-darmstadt.de
MI-Nr. 91/2013, gek
Journal
Frontiers in Ecology and the Environment